Numerous neuroscientific studies demonstrate the interaction between movement, memory, and environmental conditions. We present a new in‐the‐field tool that can be used by interior designers, environmental psychologists, and architects to understand and quantify human productivity in desk‐related work and study spaces. In this investigation, an interior space, equipped with a new generation of nonintrusive sensors and analytical algorithms synchronously measured multiple individuals and working groups. We tested the hypothesis that a positive correlation exists between stillness and cognitive function associated with self‐reported productivity. We explored, which design attributes, Seat Orientation, Zones, Table Crowdedness, and Table Types were associated with statistically significant changes in users' self‐reported productivity and micro‐movements. A mathematical model was developed to map a “stillness value” for each person across time, deriving a measurable productivity factor (PF) that could be used to synchronously assess the impact of design features in multiple users. Experiments were conducted over 12 days involving 640 academic students in a semi‐enclosed reading/study room within a recently built city public library with extensive views of the waterfront, harbor, and bay. Three‐dimensional depth‐cameras anonymously measured head and body movement while subjects worked and completed productivity surveys. Methods were validated using video recordings, sensor data, questionnaires, and observations. The results showed the PF was significantly correlated to the time spent in different Zones and was greatest at Seat Orientations furthest away from walk‐through traffic and in Zones with the highest exposure to the window wall and views. Users in these settings experienced a higher and longer‐lasting PF during the high‐performance phase of their stay.